Do you ever have to open your butt to let a fart out?

Sometimes when I'm laying in bed on my side, I'll pass gas....But, every now & again, the fart won't be strong enough to escape out into the atmosphere, and winds up trapped in a crevice .. I ultimately wind up having to open my cheeks to let it escape....This is a new phenomena for me. Has this ever happened to you? Have you found a method of rectifying the problem?